1. Field
One embodiment of the present invention relates to a disk drive apparatus having a latch mechanism of a carriage.
2. Description of the Related Art
Recently, magnetic disk apparatuses, for example, are widely used as a large capacity disk apparatus in electronic appliances such as a personal computer and the like. In general, the magnetic disk apparatus has a magnetic disk, a spindle motor for supporting and driving the magnetic disk, a rotatable carriage for supporting a magnetic head, a voice coil motor (VCM) for driving the carriage, a board unit and the like, which are arranged in a case. The VCM includes a voice coil mounted on the carriage and a pair of yokes and a permanent magnet which are attached to a case side.
Further, recently, mobile compact personal computers are becoming widespread, and a magnetic disk apparatus mounted on this type of a personal computer is required to improve resistance to a shock and the like generated when it is carried.
To satisfy the requirement, there is proposed a magnetic disk apparatus provided with a ramp load mechanism for holding a magnetic head at a predetermined position when the magnetic disk apparatus is out of operation. The ramp load mechanism has a ramp arranged outside of a magnetic disk, and when the magnetic disk apparatus is out of operation, a carriage is rotated to a retracted position located to the outer peripheral edge of the magnetic disk, and a suspension rides on the ramp. With this operation, since the magnetic head is held at a position separated from the surface of the magnetic disk.
Further, Jpn. Pat. Appln. KOKAI Publication No. 2005-235375, for example, discloses a magnetic disk apparatus provided with a latch mechanism for more improving resistance to shock as this type of a magnetic disk apparatus. When a shock is applied to the magnetic disk apparatus when it is out of operation, the latch mechanism engages with a carriage and regulates that the carriage is rotated and holds the carriage at a retracted position.
The latch mechanism has a latch member including a latch hook and is disposed so as to move between a latch position at which it can be engaged with the carriage and a release position at which the latch mechanism can be released. When the carriage moves to the retracted position, the carriage abuts the abutting portion of the latch member and moves the latch member from the release position to a latch position. Then, the latch member abuts a stop and is held at the latch position. At the same time, the carriage is held at a retracted position using the latch member as the stop. With this operation, when a shock acts on the magnetic disk apparatus, the latch member latches the carriage and regulates its pivotal movement to thereby prevent the carriage from being unintentionally moved.
In the latch mechanism arranged as described above, when the magnetic disk apparatus is not operated, the carriage comes into contact with the latch member and uses the latch member itself as the stop. Accordingly, when a strong rotational shock acts on the magnetic disk apparatus to pivot the carriage in an unload direction, that is, in the direction of the retracted position direction, a large external force acts on the latch member through the carriage to thereby elastically deform the latch member greatly. Therefore, the latch member stores distortion energy which may push out the carriage in a disk direction.
When the magnetic disk apparatus receives the strong rotational shock, the amount of push-out of the carriage (amount of rebound) is increased, and since a latch hook of the latch member cannot engage with the carriage, the magnetic head is forcibly moved on the disk. As a result, it is considered that magnetic disk apparatus may be damaged. To reduce the rebound of the carriage and the distortion energy of the latch member, it is necessary to employ countermeasures of forming the latch member of a plurality of materials. Accordingly, design is made complex and manufacturing cost is increased.